Method of desulphurizing hydrocarbon oils



May 27, 1947*7 J. c. ERNEST METHOD OF DESULPHURIZING HYDROCARBON OILS Filed Aug. 25, 1945 e /P BY Patented May 27, 1947 f METHOD OF DESULPHURIZING HYDROCARBON OILS Joseph C. Ernest, Grand Rapids, Mich., assignor to Mid-West Refneries, Inc., Grand Rapids, Mich., a corporation of Michigan Application August 25, 1945, Serial No. 612,668

3 Claims. 1

lytic material of the clay type such as fullers earth, in which the sulphur compounds present in the hydrocarbon oil are converted to more easily removable sulphur compounds. During this process of desulphurization, certain side reactions occur, which have a tendency t render the catalyst surface inactive. When this occurs, the process is continued Ain another clay tower which is connected in parallel with the rst clay tower to permit the rst clay tower to be cleaned while the process is being conducted in the second clay tower. This represents an expenditure of time and material, as well as a capital investment in a plurality of clay towers.

One object of my invention is to provide a method of continuously desulphurizing hydrocarbon oils in vapor phase by contact with a solid adsorbent catalytic material of the clay type in which the clay bed is continuously kept in active condition by subjecting it to the action of a menstruum during the process.

Another object of my invention is to provide a process of continuously treating low boiling hydrocarbons such as motor fuels in the vapor phase to increase their octane number and lead susceptibility.

Another object of my invention is to provide a method of treating hydrocarbon oils boiling within the motor fuel range to improve their color.

Other and further objects of my invention will appear from the following description.

In general, my invention contemplates the heating of a hydrocarbon oil fraction boiling within the motor fuel range and the heating of a gas oil so that the motor fuel fractions will be in the vapor phase while the gas oil will be in the form of heavy vapors and then passing the motor fuel hydrocarbon vapors and gas oil hydrocarbon vapors through a bed of solid adsorbent catalytic material of the clay type, If desired the clay tower may be kept under an elevated pressure. In this manner the heavy hydrocarbons iiush the catalyst bed and keep it active.

Some of the gas oil fractions may be in the liquid phase. I am not certain what occurs in the tower, but base my invention on the novel results achieved. Y

The accompanying drawing, which forms part of the instant specication, andwhich is to be read in conjunction therewith, shows a diagrammatic view of apparatus capable of carrying out the process of my invention.

More particularly, referring now to the drawlng, motor fuel to be treated is withdrawn from tank I through pipe 2 controlled by valve 3 and pumped by pump 4 through pipe 5 through heat exchanger B through pipe I to any suitable heating means such as pipe still 8. The gasoline may be cracked gasoline or straight run gasoline or a mixture of these. Gas oil is stored in a tank 9 from which it is withdrawn through pipe I 0 controlled by valve II and pumped by pump I2 into the pipe 5 joining the motor fuel being pumped from tank I. The gas oil may be of any suitable gravity and boiling range, as for example a gravity of thirty-nine A. P, I., and may have an initial boiling point of say 400 Fahrenheit and an end point in the neighborhood of 650 Fahrenheit. The pre-heated mixture of motor fuel and gas oil is heated first in convection heating coil I3 and then by radiant heat in coil I4 where the gasoline fractions are converted into vapors. Heat is supplied by burners I5, the flue gases being withdrawn through opening I 6. If desired the gas oil may be heated in a separate still. For example, a second separate still t4 may be provided. In such case, valve 40 would be closed and valves tl andY 48 would be open. The gas oil would then be pumped by pump I2 through pipe t2, through convection heating coil 43, through radiant heating coil 46, through pipe 41 into pipe I9 leading to the clay catalyst tower I'l. Burner 45 is provided for heating the still 44. A clay tower Il ofv any suitable design contains a bed of clay I8. The mixture of motor fuel vapors and gas oil vapors or heated liquid gas oil or all three passes into the tower I'I through pipe I8 and is adapted to be withdrawn through pipe Ell, passing through the heat exchanger 6 and thence through pipe 2| to a fractionating tower 22. A valve 23 governs the pressure between the pumps and the fractionating tower and hence the pressure in the clay tower Il. The oil and motor fuel is heated in the still 8 to a temperature in the vicinity of 600 Fahrenheit, and if desired under elevated pressure.- By way of eX- ample and not by way of limitation, the pressure may be about fty pounds per square inch.

The clay I8 may be of any suitable type. I have found that a clay obtained in the vicinity of Silvertown, Texas, is admirable for my purpose. It has the following approximate analysis:

Per cent SiOz, silica (sand) 48 -50 FezOa, iron oxide 1 5 A1203, aluminum oxide 13 14.5 CaO, lime (calcium oxide) 1I -12 MgO, magnesium oXide .5- 4 S03, sulphur trioxide 3.5

H2O, water 4 The vapors leave the fractionating tower through pipe 24 and are condensed in condenser 25. A cooling medium is supplied to the condenser through pipe 2S controlled by Valve 21. A portion of the condensate is pumped through pipe 28 by pump 29 to control the top tower temperature. The condensate passes through pipe 30 to a receiver 3i, from whence it is removed through pipe 32 controlled by valve 33 and passed to storage, Any gas which may be generated in the system may be withdrawn through pipe 34 controlled by Valve 35. The heavy fractions containing dissolved sulphur are withdrawn from the bottom of the tower 22 through pipe 3E and pumped by pump 31 to a storage .tank 38, from which they may be withdrawn through pipe 39 controlled by valve 4Q. If desired they may be pumped to the topped crude storage tank which feeds the cracking units.

Using a Michigan and West Texas crude in Dubbs cracking units, I have produceda cracked gasoline containing .25 per cent sulphur, and which was yellowish in color. Treating this cracked gasoline in accordance with my method with the Silverton clay described above, I have produced a gasoline containing `.08 per cent sulphur, and which was water White in color. Surprisingly, however, I have found that gasoline thus treated increases in octane number and furthermore the lead susceptibility of the gasoline is greatly improved. By means of my method I am able to operate continuously with a single tower. Where a plurality of towers are used I may run the towers continuously in parallel, thus increasing the output from a unit. The runs which can be madev without changing clay are thus very greatly increased and it becomes unnecessary to change the clay beds as frequently as would otherwise have to take place. Then, too, the activity of an ordinary clay bed progressively decreases. My method slows down the rate of decrease of activity to such an extent that improved results are obtained to a remarkable degree'.

It will be clear to those skilled in the art that many changes may be made in details without departing from the spirit of my invention. This is contemplated by and is within the scope of the appended claims. It is, therefore, to be understood that I am not to be limited to the particular details shown and described except within the ambit of the appended claims.

I claim:

l. In a process for desulphurizing hydrocarbons boiling within the motor fuel range in which motor fuel hydrocarbons are heated to vaporizing temperatures, the hydrocarbon vapors are passed through a bed of solid adsorbent catalytic material consisting essentially of clay whereby the sulphur compounds present in the hydrocarbon oil are converted into more easily removable sulphur compounds, the improvement comprising extending the catalytic activity of the catalyst bed by simultaneously heating a, hydrocarbon oil boiling within the gas oil range to temperature substantially equal to that to which the motor fuel hydrocarbons are heated and introducing the heated gas oil into the catalytic bed as a menstruum to remove converted sulphur compounds tending to inactivate the catalyst, removing the motor fuel vapors and gas oil from the contacting catalytic zone, separating liquid hydrocarbons from hydrocarbon vapors and condensing the vapors to obtain a treated hydrocarbon condensate boiling within the motor fuel range.

2.- Av method as in claim 1 in which the temperature to which the motor fuel hydrocarbonsar'e heated is in the vicinity of 650 F.

3. A method as in claim l in which the temperature to which motor fuel hydrocarbons are heated is in the Vicinity of 650 F., and in which the heating and catalyst contacting zones are maintained under a super-atmospheric pressure in the vicinity of 50 pounds per square inch. K n K JOSEPH C. ERNEST.

REFERENCES CITED The foilowing references are of record in the Iile of this patent:

UNITED STATES PATENTS Number Name Date 2,162,715 Hancock June 20, 1939 2,340,922 Bent et al Feb'. 8, 1944 2,260,619 Hancock Oct. 28, 1941 2,357,121 Lovell Aug. 29, 1944 1,921,478 Pier Aug. 8, 1933 2,209,458 Heard et al. July 30, 194) 

